Anonymous said in a news release that it would shut down www.bart.gov for six hours beginning at noon, twice as long as the time BART shut down cell phone service Thursday afternoon. BART officials were hoping to prevent protestors that day from communicating about police locations.

A protest of recent shootings by BART police had been planned for Thursday but failed to materialize.

Shortly after noon, the Anonymous logo appeared on the website www.mybart.org and on a separate website posted what it said was the Info User Database of myBART, which included names, addresses, phone numbers and email accounts.

The poster explained the reason for the hacking, saying it was done because “BART doesn’t give a s*** about it’s [sic] customers and riders and to show that the people will not allow you to kill us and censor us.”

“This is but the one [sic] of many actions to come,” the poster went on. “We apologize to any citizen that has his information published, but you should go to BART and ask them why your information wasn't secure with them.”

Informed by a reporter of the hacking, BART spokesman Jim Allison said it was too early to comment specifically, but he insisted that BART’s “website infrastructure, including myBART.org infrastructure, is wholly separate from any computer network involved in the operation of BART service.”

Allison said BART was monitoring the situation.

“We’re doing whatever we can to defend against any attack on the BART website,” Allison said. The main website was still operational as of 12:45 p.m.

In response to what they claim is BART "censorship," Anonymous is also planning a protest at 5 p.m. Monday at the Civic Center BART station.

“We’re going to do whatever it takes to try to maintain a safe environment for passengers in the paid area,” Allison said. He would not offer specifics, but promised an increased presence of BART police.

Allison said it was “too early to say” whether BART planned a similar shutdown of cell phone service. That shutdown has been criticized by free speech advocates.

“I’m not ruling it out,” Allison said.

Anonymous is a loosely affiliated international collective of hackers who typically get involved in computer-related issues, including support for Wikileaks.